In typical aging adults, functions related to Dorsal Lateral Prefrontal Cortex (DLPFC) activity decline. As seen in recent large longitudinal studies of intelligence and cognition, shown in FIG. 1, cognitive declines typically begin after the age of 50 or earlier, depending on the task.
Various techniques have been developed for electromagnetic stimulation of neural structures, including Transcranial Magnetic Stimulation (TMS), Deep Brain Stimulation (DBS), and transcranial Direct Current Stimulation (tDCS). These techniques have been applied for different functional and technical reasons. For example, stereotactic Transcranial Magnetic Stimulation (sTMS) has been used to provide neuromodulation of deep targets.
TMS uses electromagnetic induction to induce weak electric currents using a rapidly changing magnetic field. TMS devices use magnetic field stimulation of various target regions within the brain with magnetic coils placed in various positions around the brain of the patient. Such devices are typically large and stationary, using significant amounts of energy to generate appropriate magnetic fields. Furthermore, such devices typically require the patient to remain sufficiently stationary in relation to the magnetic coils to direct the magnetic fields to the targeted portion of the brain.
Transcranial direct current stimulation (tDCS) is a form of neurostimulation which uses constant, low current delivered through the scalp and skull to the brain area of interest via small electrodes. However, constant application of even a low current may cause irritation or burning of skin in contact with the electrodes.
Therefore, there is a need to address the above mentioned shortcomings.